The peak body for central west New South Wales councils has questioned figures used by a State MP to support formalising Joint Organisations across the state.

The Member for Barwon Kevin Humphries has urged regional councils to consider adopting Joint Organisations (JO), a statutory authority for making regional decisions on infrastructure and services, citing savings of more than 30 per cent.

Central NSW Regional Organisation of Councils (CENTROC) has been operating as a pilot JO, as a model for sharing resources and collaborating on infrastructure projects.

Chairman Bill West said local councils were already taking sufficient steps to become more efficient.

"It would be a mistake to think that Joint Organisations will be a silver bullet or provide the magic answer for any area of local government reform when we're talking about service delivery and amalgamations or boundary adjustments," Mr West said.

"I think they're two separate issues and there needs to be evidence-based facts around some of these issues and we need to be talking about the aspirations of our local communities."

JO model would not undermine local identity: Humphries

Mr Humphries said a broader conversation on council reform was needed rather than purely focussing on amalgamations.

He said formalising a JO model would not compromise local identity.

"We've done some work on some of the more remote communities, in Wilcannia for instance, and the Central Darling region, where there's been a lot of government-type programs, intervention programs and such," Mr Humphries said.

"The 30 per cent savings, that money just doesn't hit that area at all and a lot of the programs that come into country areas are managed from outside.

"I don't want to get caught up in an amalgamation debate; that's not what we want to see.

"It is about how can we work more collaboratively together but to make sure it has teeth and it's not just delivering savings but better outcomes for rate payers in our community."

But Mr West said Mr Humphries' figures were "generous" and need to be challenged.

He said proceeding down the path of Joint Organisations should not be treated as a "silver bullet" to achieving savings.

"We would see that probably, in our area, we'd expect something like 5 per cent per annum to be a generous estimate in terms of the efficiencies," Mr West said.

"There are other ways of creating efficiencies within local government, but to be looking for some magic panacea to resolve the issues would be not addressing the issues themselves."